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  • Simple typemap example in swig java

    - by celil
    I am trying to wrap a native C++ library using swig, and I am stuck at trying to convert time_t in C, to long in Java. I have successfully used swig with python, but so far I am unable to get the above typemap to work in Java. In python it looks like this %typemap(in) time_t { if (PyLong_Check($input)) $1 = (time_t) PyLong_AsLong($input); else if (PyInt_Check($input)) $1 = (time_t) PyInt_AsLong($input); else if (PyFloat_Check($input)) $1 = (time_t) PyFloat_AsDouble($input); else { PyErr_SetString(PyExc_TypeError,"Expected a large number"); return NULL; } } %typemap(out) time_t { $result = PyLong_FromLong((long)$1); } I guess the in map from Java to C would be: %typemap(in) time_t { $1 = (time_t) $input; } How would I complete the out map from C to Java? %typemap(out) time_t ??? Would I need typemaps like the ones below? %typemap(jni) %typemap(jtype) %typemap(jstype) I need this in order to wrap C functions like this: time_t manipulate_time (time_t dt);

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  • How to decode a html string using xslt

    - by John ClearZ
    I am trying to style an rss feed using xslt. I want to display an image that is stored in the tag on the feed. The problem is it is encoded to display as text on the page instead of being rendered. The following is an example of part of the string. 1). <description>&lt;img src="http&amp;#58;&amp;#47;&amp;#47;buavhw.blu.livefilestore.com&amp;#47;y1ppCokLxFJSG2cmyPdvg... I had to add extra coding to the string above to get it to appear properly here. The string below is how it appears when I paste it directly into the text box. 2). <description><img src="http&#58;&#47;&#47;buavhw.blu.livefilestore.com&#47;y1ppCokLxFJSG2cmyPdvg... If I copy and paste it again from the preview window it only then becomes the following string. 3). <description><img src="http://buavhw.blu.livefilestore.com/y1ppCokLxFJSG2cmyPdvg...

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  • What is the best way to extend restful_authentication/AuthLogic to support lazy logins by an anonymo

    - by Kevin Elliott
    I'm building an iPhone application that talks to a Ruby on Rails backend. The Ruby on Rails application will also service web users. The restful_authentication plugin is an excellent way to provide quick and customizable user authentication. However, I would like users of the iPhone application to have an account created automatically by the phone's unique identifier ([[UIDevice device] uniqueIdentifier]) stored in a new column. Later, when users are ready to create a username/password, the account will be updated to contain the username and password, leaving the iPhone unique identifier intact. Users should not be able to access the website until they've setup their username/password. They can however, use the iPhone application, since the application can authenticate itself using it's identifier. What is the best way to modify restful_authentication to do this? Create a plugin? Or modify the generated code? What about alternative frameworks, such as AuthLogic. What is the best way to allow iPhones to get a generated auth token locked to their UUID's, but then let the user create a username/password later?

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  • Function returning dictionary, not seen by calling function

    - by twiga
    Hi There, I have an interesting problem, which is a function that returns a Dictionary<String,HashSet<String>>. The function converts some primitive structs to a Dictionary Class. The function is called as follows: Dictionary<String, HashSet<String>> Myset = new Dictionary<String,HashSet<String>>(); Myset = CacheConverter.MakeDictionary(_myList); Upon execution of the two lines above, Myset is non-existent to the debugger. Adding a watch results in: "The name 'Myset' does not exist in the current context" public Dictionary<String, HashSet<String>> MakeDictionary(LightWeightFetchListCollection _FetchList) { Dictionary<String, HashSet<String>> _temp = new Dictionary<String, HashSet<String>>(); // populate the Dictionary // return return _temp; } The Dictionary _temp is correctly populated by the called function and _temp contains all the expected values. The problem seems to be with the dictionary not being returned at all. Examples I could find on the web of functions returning primitive Dictionary<string,string> work as expected.

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  • Extracting note onset from MIDI

    - by Dolphin
    Hi I need to extract musical features (note details-pitch, duration, rhythm, loudness, note start time) from a polyphonic (having 2 scores for treble and bass - bass may also have chords) MIDI file. I'm using the jMusic API to extract these details from a MIDI file. My approach is to go through each score, into parts, then phrases and finally notes and extract the details. With my approach, it's reading all the treble notes first and then the bass notes - but chords are not captured (i.e. only a single note of the chord is taken), and I cannot identify from which point onwards are the bass notes. So what I tried was to get the note onsets (i.e. the start time of note being played) - since the starting time of both the treble and bass notes at the start of the piece should be same - But I cannot extract the note onset using jMusic API. Each time it shows 0.0. Is there any way I can identify the voice (treble or bass) of a note? And also all the notes of a chord? How is the voice or note onset for each note stored in MIDI? Is this different for each MIDI file? Any insight is greatly appreciated. Thanks in advance

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  • PHP fails silently when php-code is within html tag

    - by Michal M
    PROBLEM UPDATED, READ BELOW For some reason my CI fails silently when loading view. Loading view is simply called from controller $this->load->view('templates/default.php'); Now. There are some functions in the loaded view that are not defined unless a proper helper is loaded as well. Normally, php would throw an error, but instead it fails silently here. I have no idea why. The template gets outputted till the line containing the undefined function. It took me long time to realise where my script is failing. Here's my setup: Windows 7 Ultimate Apache 2.2.15 PHP 5.3.2 with following error reporting settings: display_errors = On display_startup_errors = On error_reporting = E_ALL | E_STRICT CodeIgniter 1.7.2 Any ideas why would that be? UPDATE After further debugging, it turned out that PHP fails to report any errors when php code is inline with HTML and within the HTML tag. Now this is bizarre. This returns Fatal Error: <p><?php echo $bogus(); ?></p> This doesn't and fails silently: <p class="<?php echo $bogus(); ?>">paragraph</p> Why? :O UPDATE 2 Further investigation showed that if an error_log in PHP is specified, the errors are in fact reported in that file, but still not in the browser... Again, why? UPDATE 3 Actually my code should be slightly different. Checked another PHP installation on completely different machine and it confirmed the PHP bug. Reported here: http://bugs.php.net/bug.php?id=52040

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  • Prototype VS jQuery

    - by aSeptik
    Hi All guys! First of, thank's for your time; then i want go directly to the point by saying that, i don't want to open another "Yet Another Js VS Js" 3d , the web is almost busy of this! I want also make a premise, i have used both theese js frameworks and i love it and i know, that there are a lot of good js frameworks around, maybe better then this two; but, as you know we need to be perfomant and quickly by doing our works, so i want keep this two, that are the most famous and therefore have a great community support! now, if you are going to say me, that the choise depends on what i'm going to do!? then i can think, hey, in the end they are both javascript and they have almost the same methods and functions and for achieve a task they needs almost the same lines of code! So i want hear from you guys, from you that have really used one of theese, for a real Rich Internet Application what are the real points of force and what the weaknesses you find!? Regards.

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  • SQL Concurrent test update question

    - by ptoinson
    Howdy Folks, I have a SQLServer 2008 database in which I have a table for Tags. A tag is just an id and a name. The definition of the tags table looks like: CREATE TABLE [dbo].[Tag]( [ID] [int] IDENTITY(1,1) NOT NULL, [Name] [varchar](255) NOT NULL CONSTRAINT [PK_Tag] PRIMARY KEY CLUSTERED ( [ID] ASC )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ) Name is also a unique index. further I have several processes adding data to this table at a pretty rapid rate. These processes use a stored proc that looks like: ALTER PROC [dbo].[lg_Tag_Insert] @Name varchar(255) AS DECLARE @ID int SET @ID = (select ID from Tag where Name=@Name ) if @ID is null begin INSERT Tag(Name) VALUES (@Name) RETURN SCOPE_IDENTITY() end else begin return @ID end My issues is that, other than being a novice at concurrent database design, there seems to be a race condition that is causing me to occasionally get an error that I'm trying to enter duplicate keys (Name) into the DB. The error is: Cannot insert duplicate key row in object 'dbo.Tag' with unique index 'IX_Tag_Name'. This makes sense, I'm just not sure how to fix this. If it where code I would know how to lock the right areas. SQLServer is quite a different beast. First question is what is the proper way to code this 'check, then update pattern'? It seems I need to get an exclusive lock on the row during the check, rather than a shared lock, but it's not clear to me the best way to do that. Any help in the right direction will be greatly appreciated. Thanks in advance.

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  • Can I store SQL Server sort order in a variable?

    - by Steve Weet
    I have the following SQL within a stored procedure. Is there a way to remove the IF statement and pass the 'ASC'/'DESC' option as a variable? I know I could do the query a number of different ways, or return a table and sort it externally etc. I would just like to know if I can avoid duplicating the CASE statement. IF @sortOrder = 'Desc' BEGIN SELECT * FROM #t_results ORDER BY CASE WHEN @OrderBy = 'surname' THEN surname END DESC, CASE WHEN @OrderBy = 'forename' THEN forename END DESC, CASE WHEN @OrderBy = 'fullName' THEN fullName END DESC, CASE WHEN @OrderBy = 'userId' THEN userId END DESC, CASE WHEN @OrderBy = 'MobileNumber' THEN MSISDN END DESC, CASE WHEN @OrderBy = 'DeviceStatus' THEN DeviceStatus END DESC, CASE WHEN @OrderBy = 'LastPosition' THEN LastPosition END DESC, CASE WHEN @OrderBy = 'LastAlert' THEN LastAlert END DESC, CASE WHEN @OrderBy = 'LastCommunication' THEN LastCommunication END DESC, CASE WHEN @OrderBy = 'LastPreAlert' THEN LastPreAlert END DESC END ELSE BEGIN SELECT * FROM #t_results ORDER BY CASE WHEN @OrderBy = 'surname' THEN surname END DESC, CASE WHEN @OrderBy = 'forename' THEN forename END DESC, CASE WHEN @OrderBy = 'fullName' THEN fullName END DESC, CASE WHEN @OrderBy = 'userId' THEN userId END DESC, CASE WHEN @OrderBy = 'MobileNumber' THEN MSISDN END DESC, CASE WHEN @OrderBy = 'DeviceStatus' THEN DeviceStatus END DESC, CASE WHEN @OrderBy = 'LastPosition' THEN LastPosition END DESC, CASE WHEN @OrderBy = 'LastAlert' THEN LastAlert END DESC, CASE WHEN @OrderBy = 'LastCommunication' THEN LastCommunication END DESC, CASE WHEN @OrderBy = 'LastPreAlert' THEN LastPreAlert END DESC END END

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  • Storing User Information in Session with aspNetMembershipProvider

    - by Muhammad Adeel Zahid
    Hi Everyone, i m developing an application in .NET mvc2. i m using aspnetMembershipProvider for User registration and related activities. i need some custom information about user that i stored in a separate table (sysUser for example) and linked it to aspnetUser table through foreign key. after Login i need to fetch user's credentials from sysUser table and push it to the session. For this Account controller's Logon method seemed best to me and i pasted following code in my Logon ActionResult if (!ValidateLogOn(userName, password)) { return View(); } FormsAuth.SignIn(userName, rememberMe); ApplicationRepository _ApplicationRepository = new ApplicationRepository(); MembershipUser aspUser = Membership.GetUser(userName); SessionUser CurrentUser = _ApplicationRepository.GetUserCredentials(aspUser.ProviderUserKey.ToString()); //Session["CurrentUser"] = CurrentUser; if (!String.IsNullOrEmpty(returnUrl)) { return Redirect(returnUrl); } else { return RedirectToAction("Index", "Home"); } The code is working perfectly for me and put my desired information in the session but the thing is that if a user selects Remember me and on his next visit he won't have to Log in and i would not find my desired information in the Session. Can anyone guide me where should i put my code that stores the user information in the session. any Help is Highly appreciated Regards Adeel

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  • Javascript "this" variable confusion

    - by Assaf M
    Hi I am currently reading the book "Javascript: The Good Parts" and was playing with Functions. I produced a test script to test some properties and I am somewhat confused by the results. Here is the code: <h3>Object</h3> <div style="padding-left: 10px;"> <script type="text/javascript"> function outterF() { document.writeln("outterF.this = " + this + "<br>"); function innerF() { document.writeln("innerF.this = " + this + "<br>"); return this; }; var inner = innerF(); return this; } document.writeln("<b>From Inside:</b><br>"); var outF = outterF(); var inF = outF.inner; document.writeln("<br>"); document.writeln("<b>From Outside:</b><br>"); document.writeln("outterF.this = " + outF + "<br>"); document.writeln("innerF.this = " + inF + "<br>"); </script> </div> Result is: Object From Inside: outterF.this = [object Window] innerF.this = [object Window] From Outside: outterF.this = [object Window] innerF.this = undefined Notice that outF.inner returns "undefined", is that some kind of a language bug? Obviously, outF.inner points to Window object that has nothing to do with my object but shouldn't it be at least pointing to a Function object instead? Thanks -Assaf

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  • Asp.net mvc - trying to display images pulled from db \

    - by Trey Carroll
    //Inherits="System.Web.Mvc.ViewPage<FilmFestWeb.Models.ListVideosViewModel>" <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <h2>ListVideos</h2> <% foreach(BusinessObjects.Video vid in Model.VideoList){%> <div class="videoBox"> <%= Html.Encode(vid.Name) %> <img src="<%= vid.ThumbnailImage %>" /> </div> <%} %> </asp:Content> //ListVideosViewModel public class ListVideosViewModel { public IList<Video> VideoList { get; set; } } //Video public class Video { public long VideoId { get; set; } public long TeamId { get; set; } public string Name { get; set; } public string Tags { get; set; } public string TeamMembers { get; set; } public string TranscriptFileName { get; set; } public string VideoFileName { get; set; } public int TotalNumRatings { get; set; } public int CumulativeTotalScore { get; set; } public string VideoUri { get; set; } public Image ThumbnailImage { get; set; } } I am getting the "red x" that I usually associate with image file not found. I have verified that my database table shows after the stored proc that uploads the image executes. Any insight or advice would be greatly appreciated.

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  • How close can I get C# to the performance of C++ for small intensive tasks?

    - by SLC
    I was thinking about the speed difference of C++ to C# being mostly about C# compiling to byte-code that is taken in by the JIT compiler (is that correct?) and all the checks C# does. I notice that it is possible to turn a lot of these functions off, both in the compile options, and possibly through using the unsafe keyword as unsafe code is not verifiable by the common language runtime. Therefore if you were to write a simple console application in both languages, that flipped an imaginary coin an infinite number of times and displayed the results to the screen every 10,000 or so iterations, how much speed difference would there be? I chose this because it's a very simple program. I'd like to test this but I don't know C++ or have the tools to compile it. This is my C# version though: static void Main(string[] args) { unsafe { Random rnd = new Random(); int heads = 0, tails = 0; while (true) { if (rnd.NextDouble() > 0.5) heads++; else tails++; if ((heads + tails) % 1000000 == 0) Console.WriteLine("Heads: {0} Tails: {1}", heads, tails); } } } Is the difference enough to warrant deliberately compiling sections of code "unsafe" or into DLLs that do not have some of the compile options like overflow checking enabled? Or does it go the other way, where it would be beneficial to compile sections in C++? I'm sure interop speed comes into play too then. To avoid subjectivity, I reiterate the specific parts of this question as: Does C# have a performance boost from using unsafe code? Do the compile options such as disabling overflow checking boost performance, and do they affect unsafe code? Would the program above be faster in C++ or negligably different? Is it worth compiling long intensive number-crunching tasks in a language such as C++ or using /unsafe for a bonus? Less subjectively, could I complete an intensive operation faster by doing this?

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  • Communication between modules

    - by David Elentok
    I have an application that consists from the following three modules: Search (to search for objects) List (to display the search results) Painter (to allow me to edit objects) - this module isn't always loaded (Each object is a figure that I can edit in the painter). When I open an object in the painter it's added to the objects that are already in the painter and I can move it and alter it. I'm using an object similar to the EventAggregator to communicate between the modules. For example, to show the search results I publish a "ShowList" event that is caught by the List module (I'm not sure this is the best way to do this, if anyone has better idea please comment...). One of the features of the search module requires it to get the selected object in the painter (if the painter is available), and I'm not sure what would be the best way to do that... I thought of these solutions: Whenever the selected object in the painter changes it will publish a "PainterSelectedObjectChanged" event which will be caught by the search module and stored for later use. When the selected object is needed by the search module it will publish a "RequestingPainterSelectedObject" event which will be caught by the painter module. The painter module will then set the "SelectedObject" property in the EventArgs object, and when the publish is complete and we're back in the search module we will have the painter's selected object in the EventArgs object. What do you think? what is the right way to do this?

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  • Silverlight MVVM binding seems not to work

    - by Savvas Sopiadis
    Hi everybody! Building my first SL MVVM application (Silverlight4 RC) and have some issues i don't understand. Having a WPF background i don't know what is going on here: ViewModel has several properties, in which one is called SelectedRecord. This is a get only property and is defined like this: public Culture SelectedRecord { get { return culturesView.View.CurrentItem as Culture; } } As you can see it is gets the current value of a CollectionViewSource (called culturesView). So if i select a Culture, the SelectedRecord (gets a value directly from within the CollectionViewSource) as expected. (Actually there is a datagrid control bound to the CollectionViewSource, hence it is possible to change the selected item) OK. Now to the View . There are several views which access this ViewModel and in particular there is one which shows the values of the aforementioned property SelectedRecord (let's call it the EditView). To show this EditView there is a button (which has its Command property bound to an ICommand in the ViewModel) which functions (the first time) as expected. This means: 1st try : i select a record, switch to EditView, outcome: selected record values are shown (as expected!!). 2nd try: switch back to datagrid, select another record, switch to EditView, outcome: the values of the previous shown record are shown again!!! WHY?? First i thought that the SelectedRecord has not the correct value set, but i was mistaken: it HAS the correct value! So it should be shown!? What am i missing? In WPF this would work!! Thanks in advance

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  • What java web application framework to use?

    - by frohiky
    One of the main products of my company is an Oracle Forms (and Reports) based application, that "needs" to be re-written in another technology. Why? Users want a more rich interface experience, and we want, preferably, to reduce costs with an open source application server. For this (HUGE) project, we intend to use a java web application framework, keep these points in mind: We have: hundreds of tables on our database (the ORM must be as flexible as possible); some logic which is (and will still be) based on PL/SQL procedures/functions/packages; a lot of CRUDs (the application itself is of an considerable size); a demand to work with/generate documents and workflows; an intranet based user environment; We want: to offer a RIA interface experience; use (if possible) an open source app server; a rapid (as possible) development framework; a somewhat mature framework with a "wise" roadmap (and a considerable community support); a MVC approach combined with JS or GWT widgets (e.g. Vaadin or SmartGWT); Well, in the past weeks I've read a lot of posts, Q&As on stackoverflow, and much more: Wicket, JSF, Tapestry, Grails, GWT, Struts2, Play, Spring, Seam, Echo, .... the list goes on! I've even researched about Alfresco..! The obvious question: Which one to use? At this time, any insight, recommendation, shared experience, advice will be more then welcome!

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  • Find & Replace - using a Regex for this?

    - by Jack W-H
    Hey folks. Regexs make me cry, so, I came here for help. I'm looking for some tips on Find & Replace in Panic's Coda. I know the F&R is pretty advance but I'm just looking for the best way to do this. I'm trying to rewrite a 'template engine' (very basic) I have going on with a webapp I'm coding in PHP (CodeIgniter). Currently I'm calling my template like so: $this->load->view('subviews/template/headerview'); $this->load->view('subviews/template/menuview'); $this->load->view('subviews/template/sidebar'); $this->load->view('The-View-I-Want-To-Load'); // This is the important line $this->load->view('subviews/template/footerview'); However it's inefficient using five lines of code every time I want to load up a different page, in every different controller. So I rewrote it like this: $data['view'] = 'The-View-I-Want-To-Load'; $this->load->view('template',$data); That way if I need to make any major changes to the design it can easily be done from the template.php view file (which contains the header, menu, sidebar views etc. etc.). However I use the previous 5-lines all over the place in many different controllers and functions. So, my question is --- How can I find and replace the old template engine (5 lines of code) for the new one - substituting in the name of the view in the important, unique line for the one in $data['view]? Does that make any sense?! If not I'll try and rephrase! I mean, is there a way of doing this via a Regex or something? Or am I on completely the wrong lines here? Thanks for your help Jack

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  • Data Flow Object Graph and An Execution Engine for it

    - by M Dotnet
    I would like to build a custom workflow engine from scratch. The input to this workflow is a data flow diagram which is composed of a series of activities connected together through lines where each each represent the data flow. Each activity can export multiple outputs. Activities are complex math functions but the logic is hidden from the user. My workflow engine job is to execute the given data flow diagram. Each activity within the data flow diagram is a custom activity and each activity can output different outputs. How do you suggest to model the data flow diagram object? I need to be able to construct the data flow diagram problematically (no need for drag and drop) but I need to display the final result graphically (for display and debugging purposes). Are there any libraries out there that I could use? Should I keep the workflow presentable as an xml? I know that there are many projects out there trying to essentially doing similar thing by building such workflow engines but I need something light weight and open source. I do not need any state machine execution engine and mine is primarily sequential workflow with fork and join capabilities. My activities are wrappable as basic C# classes and I do NOT want to use anything as heavy as .NET workflow foundation.

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  • Executing javascript script after ajax-loaded a page - doesn't work

    - by Deukalion
    I'm trying to get a page with AJAX, but when I get that page and it includes Javascript code - it doesn't execute it. Why? Simple code in my ajax page: <script type="text/javascript"> alert("Hello"); </script> ...and it doesn't execute it. I'm trying to use Google Maps API and add markers with AJAX, so whenever I add one I execute a AJAX page that gets the new marker, stores it in a database and should add the marker "dynamically" to the map. But since I can't execute a single javascript function this way, what do I do? Is my functions that I've defined on the page beforehand protected or private? ** UPDATED WITH AJAX FUNCTION ** function ajaxExecute(id, link, query) { if (query != null) { query = query.replace("amp;", ""); } if (window.XMLHttpRequest) { // code for IE7+, Firefox, Chrome, Opera, Safari xmlhttp=new XMLHttpRequest(); } else { // code for IE6, IE5 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } xmlhttp.onreadystatechange=function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { if (id != null) { document.getElementById(id).innerHTML=xmlhttp.responseText; } } } if (query == null) { xmlhttp.open("GET",link,true); } else { if (query.substr(0, 1) != "?") { xmlhttp.open("GET",link+"?"+query,true); } else { xmlhttp.open("GET",link+query,true); } } xmlhttp.send(); }

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  • Need some help to determine the amount of recursive calls in PHP

    - by Ben Fransen
    Hi all, I've got a, I think fairly easy question, but this is bugging me for a while now. So I figured, maybe I can get some help here. Since recursive functions are always a bit tricky, and sometimes a bit unclear to me, I keep struggling to create a nice working solution to get my menudata. In one of my classes I have this function, which gives me all menu-items recursivly. The thing I want is to determine at which recursionlevel a certain object was retrieved so I can create a nicely looking HTML output with indents for the levels of nesting. public function GetObjectList($parentID = 0, $objectlist = null) { if(is_null($objectlist)) { $objectlist = new ObjectList("Model_Navigation"); } $query = MySQL::Query("SELECT * FROM `Navigation` WHERE `WebsiteID` = ".SITE_ID. " AND `LanguageID` = ".LANG_ID." AND `ParentID` = ".$parentID); while($result = MySQL::FetchAssoc($query)) { $object = new Model_Navigation(); $object->ID = $result["ID"]; $object->WebsiteID = $result["WebsiteID"]; $object->LanguageID = $result["LanguageID"]; $object->ParentID = $result["ParentID"]; $object->Name = $result["Name"]; $object->Page = Model_Page::GetObjectByID($result["PageID"]); $object->ExternalURL = $result["ExternalURL"]; $object->Index = $result["Index"]; $object->Level = [here lies my problem]; $objectlist->Add($object); self::GetObjectList($object->ID, $objectlist); } return $objectlist; } Hope to hear from you! Greetings from Holland, Ben Fransen

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  • Optimizing processing and management of large Java data arrays

    - by mikera
    I'm writing some pretty CPU-intensive, concurrent numerical code that will process large amounts of data stored in Java arrays (e.g. lots of double[100000]s). Some of the algorithms might run millions of times over several days so getting maximum steady-state performance is a high priority. In essence, each algorithm is a Java object that has an method API something like: public double[] runMyAlgorithm(double[] inputData); or alternatively a reference could be passed to the array to store the output data: public runMyAlgorithm(double[] inputData, double[] outputData); Given this requirement, I'm trying to determine the optimal strategy for allocating / managing array space. Frequently the algorithms will need large amounts of temporary storage space. They will also take large arrays as input and create large arrays as output. Among the options I am considering are: Always allocate new arrays as local variables whenever they are needed (e.g. new double[100000]). Probably the simplest approach, but will produce a lot of garbage. Pre-allocate temporary arrays and store them as final fields in the algorithm object - big downside would be that this would mean that only one thread could run the algorithm at any one time. Keep pre-allocated temporary arrays in ThreadLocal storage, so that a thread can use a fixed amount of temporary array space whenever it needs it. ThreadLocal would be required since multiple threads will be running the same algorithm simultaneously. Pass around lots of arrays as parameters (including the temporary arrays for the algorithm to use). Not good since it will make the algorithm API extremely ugly if the caller has to be responsible for providing temporary array space.... Allocate extremely large arrays (e.g. double[10000000]) but also provide the algorithm with offsets into the array so that different threads will use a different area of the array independently. Will obviously require some code to manage the offsets and allocation of the array ranges. Any thoughts on which approach would be best (and why)?

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  • How do I tell gcc to relax its restrictions on typecasting when calling a C function from C++?

    - by Daryl Spitzer
    I'm trying to use Cmockery to mock C functions called from C++ code. Because the SUT is in C++, my tests need to be in C++. When I use the Cmockery expect_string() macro like this: expect_string(mock_function, url, "Foo"); I get: my_tests.cpp: In function ‘void test_some_stuff(void**)’: my_tests.cpp:72: error: invalid conversion from ‘void*’ to ‘const char*’ my_tests.cpp:72: error: initializing argument 5 of ‘void _expect_string(const char*, const char*, const char*, int, const char*, int)’ I see in cmockery.h that expect_string is defined: #define expect_string(function, parameter, string) \ expect_string_count(function, parameter, string, 1) #define expect_string_count(function, parameter, string, count) \ _expect_string(#function, #parameter, __FILE__, __LINE__, (void*)string, \ count) And here's the prototype for _expect_string (from cmockery.h): void _expect_string( const char* const function, const char* const parameter, const char* const file, const int line, const char* string, const int count); I believe the problem is that I'm compiling C code as C++, so the C++ compiler is objecting to (void*)string in the expect_string_count macro being passed as the const char* string parameter to the _expect_string() function. I've already used extern "C" around the cmockery.h include in my_tests.cpp like this: extern "C" { #include <cmockery.h> } ...in order to get around name-mangling problems. (See "How do I compile and link C++ code with compiled C code?") Is there a command-line option or some other means of telling g++ how to relax its restrictions on typecasting from my test's C++ code to the C function in cmockery.c? This is the command I'm currently using to build my_tests.cpp: g++ -m32 -I ../cmockery-0.1.2 -c my_tests.cpp -o $(obj_dir)/my_tests.o

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  • How to work threading with ConcurrentQueue<T>.

    - by dboarman
    I am trying to figure out what the best way of working with a queue will be. I have a process that returns a DataTable. Each DataTable, in turn, is merged with the previous DataTable. There is one problem, too many records to hold until the final BulkCopy (OutOfMemory). So, I have determined that I should process each incoming DataTable immediately. Thinking about the ConcurrentQueue<T>...but I don't see how the WriteQueuedData() method would know to dequeue a table and write it to the database. For instance: public class TableTransporter { private ConcurrentQueue<DataTable> tableQueue = new ConcurrentQueue<DataTable>(); public TableTransporter() { tableQueue.OnItemQueued += new EventHandler(WriteQueuedData); // no events available } public void ExtractData() { DataTable table; // perform data extraction tableQueue.Enqueue(table); } private void WriteQueuedData(object sender, EventArgs e) { BulkCopy(e.Table); } } My first question is, aside from the fact that I don't actually have any events to subscribe to, if I call ExtractData() asynchronously will this be all that I need? Second, is there something I'm missing about the way ConcurrentQueue<T> functions and needing some form of trigger to work asynchronously with the queued objects?

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  • Matlab - Propagate points orthogonally on to the edge of shape boundaries

    - by Graham
    Hi I have a set of points which I want to propagate on to the edge of shape boundary defined by a binary image. The shape boundary is defined by a 1px wide white edge. I also have the coordinates of these points stored in a 2 row by n column matrix. The shape forms a concave boundary with no holes within itself made of around 2500 points. I want to cast a ray from each point from the set of points in an orthogonal direction and detect at which point it intersects the shape boundary at. What would be the best method to do this? Are there some sort of ray tracing algorithms that could be used? Or would it be a case of taking orthogonal unit vector and multiplying it by a scalar and testing after multiplication if the end point of the vector is outside the shape boundary. When the end point of the unit vector is outside the shape, just find the point of intersection? Thank you very much in advance for any help!

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  • Is there anyway to carry a value in php forward to a second page?

    - by Henry Aspden
    I have created a php site, and previously it was listing only products with defined values. I have now changed it to include an array of products for example all products WHERE id = "spotlights" and this works great so it means I can add new products just to the database, but I still have to add the second page manually. e.g going from the product div on the main page, through to www.example.com/spotlight_1.php Is there anyway in PHP to carry the data from my index.php e.g. the ID through to the next page? so that I can have a template product.php page, and I can use a database pull to echo the product information required. So on index.php i click on the product with ID="1" and on the product.php page, it loads the relevant data for product 1. I can write the php SQL/mySQL calls myself, its just the way to carry accross a value from the previous page which I dont understand Regards Henry p.s. all the IDs and things are stored in the database already as 1 to 3digit values e.g. 3 or or 93 or 254 Any advice as always is greatly appreciated Regards Henry

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